1. Field of the Invention
This invention relates to seats for use with bicycles, tricycles or similar wheeled vehicles. Specifically, this invention relates to bicycle seats which are adjustable about a horizontal axis transverse the longitudinal axis of the frame of the bicycle, and particularly to adjustability while the seat is being occupied by the rider.
2. Statement of the Art
Adjustability of bicycle seats is a feature well documented in the patent literature. Many mechanisms have been designed to provide adjustability to the height of the bicycle seat relative to the frame of the bicycle. That is, the seat may be adjusted up or down so that the rider's seat is higher or lower than the handlebars. Examples of such teachings are U.S. Pat. No. 3,408,090 to Fritz, et al., issued Oct. 29, 1968; U.S. Pat. No. 3,858,906 to Wright, issued Jan. 7, 1975; U.S. Pat. No. 5,024,413 to Papp, issued Jun. 18, 1991; and Japanese Utility Model Publication (Kokoku) No. 63-558, published Jan. 7, 1988.
Another form of adjustability of a bicycle seat has been provided in movability of the seat along a horizontal axis aligned with the longitudinal axis of the frame. By such adjustment, the rider may position his seat farther away from or closer to the handlebars. Examples of such teachings are German Patentschrift NR. 209292 issued May 25, 1960; U.S. Pat. No. 4,421,357 to Shimano, issued Dec. 20, 1983; U.S. Pat. No. 4,772,069 to Szymski, issued Sep. 20, 1988; U.S. Pat. No. 5,007,675 to Musto, et al., issued Apr. 16, 1991; and U.S. Pat. No. 5,048,891 to Yach, issued Sep. 17, 1991.
A unique structure providing combined vertical and horizontal adjustment to a bicycle seat is disclosed by U.S. Pat. No. 4,919,378 to Iwasaki, et al., issued Apr. 24, 1990. The intended purpose of the adjustment structure in the Iwasaki patent is to provide counteradjustment to the seat when the seat post is raised thereby shifting the seat farther from the handlebars. The seat of Iwasaki remains horizontal at all times, however.
Very little if any attention has been directed to providing a seat which is adjustable about a horizontal axis transverse the longitudinal axis of the bicycle frame or seat. Rotational adjustment is disclosed in U.S. Pat. No. 3,302,970 to Rizzato, issued Feb. 7, 1967, in which an arcuate ratcheting bracket facilitates rotation of the seat about an axis point below the seat. However, the Rizzato seat is designed to maintain the seat in a horizontal orientation in response to adjustment of the seat post. U.S. Pat. No. 4,978,167 to Harvey, issued Dec. 18, 1990, also teaches a structure providing a slight downward tilt of the seat to encourage shifting of the rider's body weight to a body support associated with the horn of the seat.
The aforementioned mechanisms were developed in response to riding trends of the time, which typically comprised riding on flat, well-maintained roads in the city. However, in the past decade or so there has been an upsurge in the popularity of riding bicycles in rough terrain areas like mountainsides, dunes, and the like. Thus, bicycles have been developed, popularly called "mountain bikes" or BMX bikes, which provide certain features facilitating travel through other than flat, smooth terrain. Under certain conditions of riding through rough terrain, it is particularly desirable, and perhaps necessary, for the rider to position his or her body at an angle to the longitudinal frame of the bicycle in order to adjust the rider's center of gravity and to distribute his weight to facilitate movement. For example, when riding uphill, it is advantageous for the rider to shift his body weight forward on the bicycle to provide more leverage on the pedals. When riding downhill, the rider's body is preferably shifted backward on the seat to counterbalance the downward force of gravity.
It can be seen, therefore, that it would be advantageous to provide a seat having structure providing adjustability of the seat about a horizontal axis transverse the longitudinal axis of the bicycle frame in order to retain the bicycle seat squarely, and comfortably, beneath the rider under all types of riding conditions. It would also be advantageous for such structure to be operable while the rider is seated on the bicycle, and adjustable within a matter of seconds.